Slide shifter for stereopticons



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iiitili@ STATES PATENT l'ii;

HERMAN A. DE VRY, OF CHICAGO, ILLINOIS, ASSIGITOR TO THE DE 'VRYCORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

`SLIDE SHIFTER FOR STEREOITICONS.

Application led July 25, 1921.

The invention relates to devices for shifting slides in stereopticons.

The object of the invention is to provide an improved slide shifterwhich is simple in construction, yenicient in operation and in whichtherslides, after being released, are positively displaced from a lowersupport and thus released vto fall by gravity and the weight ofsuperimposed slides.

The invention consists in the several novel features hereinafter setforth and more particularly defined by claims at the conclusion hereof.

.in the drawings: F 1 is a side elevation of a portion of a'stereopticonembodying the invention, parts being shown in section. Fig. 2 is a frontview. 3 is a vertical section on an enlarged scale. F ig. e is aperspective of the several parts of the releasing device. Fig. 5 is adetail of the vieldable stop device for the rotatable releasing device.i

|lrhe invention ispexemplilied in a slide shifter applied to astereopticon comprising a lamp-house 8, a condenser 9 and a slideholderor guide for positioning the slides during projection. This guide orholder comprises a wall 11 secured to the condenser casing 9a and inwhich is formed an opening through which light is projected, sides 12between which the slides are adaptedto pass, and front flanges ormembers 13 adapted to lap the margins of the front of a slide in theholder. The holder-sides 12 are disposed to confine the plate againstedgewise lateral displacement and the flanges or meinbers 13 prevent theslide 14 from forward displacement. Springs 15 are adapted to pressagainst the margins of the slides backwardly to hold them iiatly againstthe front of plate 11. These springs are of insufficient tension toprevent the slides from falling through the guides by gravity butsufficient to hold them against the front of the plate 11. Front flanges13 are spaced from wall 11 and terminate at a point above the lower endof a slide positioned for projection, so as to permit the lower end ofthe slide to be displaced forwardly from the support for its lower edge.The holder eX- tends upwardly suliiciently to retain a second slideplaced on the upper edge of the lirst slide.

A rotatable slide-support and releasing device 17 is adapted tosuccessively support nected by strips 19a Serial No. 487,296.

vthe slides in the guide and to shift their lower margins forwardly toclear the support so they will fall out of the holder by gravity. Thisreleasing device comprises a shaft 18 which is journalled in bearings inthe sides 12 and a series of members 19. A hand-wheel 20 is secured toshaft 17 so that the releasing device may be rotated step-bystep. Eachmember 19 of the releasing ce'- vice is adapted to serve as a supportengaged by the lower edge of a slide to retain it vertically in theguide and to positively deflect the lower portion of the slideforwardly, so it will clear the member acting to support the slide. Ishifted to deflect a slide forwardly, it passes into position to form arest for the next slide descending in the holder. As each member isrotated 'from its horizontal*supporting position, it is inclineddownwardly and forwardly and thus facilitates the initial clescent ofthe slide. The members 19 are preferably formed of platesof sheet-metal,each bent to form a pair of members conadapted to partly Vencircle theshaft 18, the strips of'one pair being offset relatively to those on theother. The strips are usually soldered to the shaft 18.

A wheel 21, provided with arms or teeth 22 corresponding in number tothe number of members 19 on the releasing device, is fixed to the shaft18 outside of the guideway and a fiat spring 28 is bent, so that it willbear on the wheel, as shown in Fig. 1, and so that the releasing devicewill be yieldingly arrested after each 900 step and so the springs willact to impel the releasing device during the latter portion of thecycle. A curved retainer plate 25 is supported under the guideway tocatch the plates released therefrom and to retain them so they can beremoved laterally.

In operation, the forwardly positioned member 19 of the rotatablesupport and releasing device 17 will arrest a slide deposited into theguideway and the springs 15 will press the slide backwardly against thefrontof the plate 11 into correct position for projection. Vhen theslide is to be changed, the slide to be next exposed is deposited on thetop of the first slide so that the second slide will be in readiness toquicl ly drop into correct position for exposure as the first slide isremoved. The operator will As each member is y ci then turn thereleasing device a quarter of a revolution under guidance of theyieldable stop-device 2l, 23. Such rotation will cause the member 19 inthe rear of the lower margin of the plate to engage the back of theslide and positively push the lower portion of the slide forwardly,While the member on which the slide has been resting Will be inclineddownwardly, so that the slide. will be dellected forwardly of thereeasing device and will drop by gravity onto the retainer 25. i V

A characteristic of this construction is that suchmember. 19 positivelydetiects the slide, and theny passes into position to arrest the nextslide before it permitted to drop bythe dropping of the irst s lide.Another characteristic is' that the Weight of' the sec ond slide isutilized to discharge the exposed slide from the member. i

The invent-ion is not to be understood` as restricted to the details setforth, since these may be modilied within the scopel of the appeudedvlaims, Without departing 'from the spirit and scope ci' the invention.

Having thus described the invention, what I claim as new andV desire tosecure by Letters Patent, is: i

l. In a slide shifter for stereopyticons, the combination of a holdertorming` a vertical guideivay adapted, to receive a pluralty of alignedslides With the lower` edgeo't, one slide resting on the topedgeot,another, anda device, rotatable stepTbyf-step and. comprisingl a`plurality oilmembers, each adapted in ro? tative successionto displacetransversely the lower slide from the guideway and to support the nextslide.

2. In a slide shifter for stereopticons, the

combination of a holder forming a vertical guideway adapted to receive aplurality of aligned slides with the lower edge of one slide resting onthe top edge of another, a device rotatable step-by-step and comprisinga plurality of members, each adapted in rotative succession to displacetransversely the lower slide from the guidevvay and to support the next,and spring means to yieldingly hold the device so the members Will besuccessively positionedY to support the slides.

3. In a slide shifter for stereopticons, the combination of a holderforming.. a vertical guidevvay adapted to receive a plurality of alignedslides With thev lower edgeV of one slide resting on the top edge ofanother, a device rotatable step-by-step and comprising a shai't and aplurality of outwarlfdy ext-end ing members connected to said shaft,each member being adapted in rotative succession to displacetransversely the lower slide from,

slides, of a rotatable device comprising a shatt, a pluralityoit`supporting and deflecting members each formed of a plurality of integrallongitudinally extendingsheet metal blades secured onl said shaft, and4means for rotating the shaft.

HERMAlSlw A. DE VRY.

